Refrigerating construction



Dec. 28, 1937. F. H. HIBBERD 2,103,723

REFRIGERATING CONSTRUCTION Filed March 23, 1954 INVENTOR.

lz a c t/vlllfiliberd UNITED STATES PATENT OFFICE 2,103,723REFRIGERATING CONSTRUCTION Frederick H. Hibberd, Bayside, N. Y.,assignor to Inger-soll-Rand Company, Jersey City, N. 1., B corporationof'New Jersey Application March 23,1934, Serial No. 716,947

9 Claims.

This invention relates to a refrigerating construction, and particularlyto a device and method for controlling a refrigerating system in which aliquid refrigerating agent or medium is employed to bring about therequired cooling effect.

The invention is adapted for use with a multiple unit type ofrefrigerating apparatus in which refrigeration by evaporation isaccomplished in one or more units according to the load requirements. Anobject of the invention is to provide means whereby the refrigerationoutput of the system may be controlled by shutting down or starting upone or more units without excessive manipulation of valves.

For refrigerating systems employing a nonvolatile substance, such aswater, as the refrigerant or'cooling medium, an evaporator in the' formof a container for water to be chilled is employed. The pressure in thisevaporator is kept at a relatively low point, so that when water isadmitted thereto at a given temperature, some of p the water isvaporized at once. -In this way aaccomplished by a steam ejector whichexhausts to a condenser wherein the discharge of the ejector isliquefied. With an evaporator having a single chamber and steam ejectorsuch a system' will serve quite well at approximately fixed orpredetermined loads, but it is quite unsuitable for practical operationwhen the load varies. Hence if such a system is built for a rated loadit cannot be operated advantageously to give a reduced output, and if itis built for a small load the output cannot greatly be increased. Thisis due to the fact that the capacity of the steam ejector or steam jetbooster, that is, the pounds of water vapor evacuated thereby at fixedsuction pressure determined bythe pressure in the evaporator itself, issubstantially constant, regardles of the amount of steam being used.Further, it is a characteristic of the steam jet booster that its steamflow must be maintained at the rated value so long as the suctionpressure (or the chilled water temperature) in the evaporator anddisremain at their normal values. But with a reprises several evaporatorchambersand steam ejectors, connected in multiple and adapted to workwith either all of its evaporator chambers and ejectors, or less thanall of said chambers and ejectors in operation, the load can be variedwithin quite widely separated limits, steam can be saved underconditions of reduced load and the consumption or expenditure of poweris thus adjusted to the quantity of refrigerating effect that isactually obtained.

This invention is especially designed to be employed with refrigeratingsystems including a plurality of chambers for evaporating and coolingwater and a steam ejector for each chamber, with proper connections forthe operation of one or more of said chambers; a further object thereofis to provide a refrigeratingsystem having multiple evaporatorchambers-with supply means disposed in permanent free communication withsaid chambers and so arranged that water to be chilled is admitted toonly the chambers of the evaporator which really are in operation anduse, the inflow of water to any chamber which is cut out beingautomatically interrupted so that said chamber remains virtually emptyuntil the operation thereof is resumed.

Another object of the invention is to provide a refrigerating system,having a water evaporator comprising a chamber or chambers of suchinterior design that the admission of water thereto is at once preventedwhenever the evacuation of water vapor therefrom is stopped. This modeof action is obtained solely as the result of working conditions in anychamber which is thus put out of operation, and no valves or the likeelements to be manipulated in the water supply connections are needed.

An additional object of the invention is to provide a refrigeratingconstruction embracing an evaporator with one or more chambers in whichpart of a liquid refrigerant is vaporized to cool the main body of saidrefrigerant, and with another chamber in which no substantialrefrigerating effect is produced and which has for its function theautomatic maintenance of the proper level of the chilled water in theother chambers.

The objects and advantages of the invention are completely set out inthe following description, but the disclosure is explanatory only, andmany changes that are embraced within the principle of the invention canbe made, as indicated by the broad terms in which the appended claimsare expressed.

In the drawing, Figure 1 shows an outline of a refrigeratingconstruction according to the invention, partly in section,

Figure 2 is a sectionalview taken on the line 2-2 of Figure 1, and

Figure 3 is a view similar to Figure 2 showing an evaporator chamberthat is not operating.

In the drawing the same numerals identify the same part throughout.

I show at l a water evaporator having a supply pipe 2 and an exhaust ordelivery pipe 3, the water being admitted to the evaporator i, and afterbeing cooled therein, being withdrawn through the conduit or header 3and carried oif thereby. The evaporator G contains several compartmentsor chambers 4, 5, 5, and 7, formed by the ends of the evaporator andtransverse partitions 8, a portion of the incoming water being vaporizedin one or more of these chambers. The water vapor is' removed by meansof suitable evacuator members, such as steam ejectors or steam jetboosters 20. The steam ejectors remove the water vapor trom the chambersand in so doing maintain the high vacuum necessary for vaporization andchilling of the incoming water to the temperature desired. Theseboosterscommunicate with the top of the chambers and discharge into asteam exhaust pipe 9. This exhaust pipe communicates with a conventionaltype of condenser wherein the evacuated vapors and operating steam arecondensed at a somewhat higher pressure than that in any of the chamberswhere water vapor is thus created. The steam ejectors for all thechambers of the evaporator l are supplied from a common steam line H).

The terminal portion of the water supply pipe 2 is inside the evaporatorI, and has sections ll in the chambers 4, 5, 6, and I. It delivers tothe chamber 4 through a comparatively small upright branch pipe or welll2, and the other chambers through lateral branches indicated in Figure2 at l3. The common delivery pipe 3 communicates with the bottom of allthe chambers through branches or riser pipes I4 by way of outletopenings l5. The communication between the conduit 3 and any of thechambers of the evaporator is always free because no valves are employedin either the delivery pipe 3 or any of the branches M. So long as thevarious chamhers are in operation and water is vaporized therein andwater vapor removed therefrom, the water in the various chambers will becooled to the required extent. If, however, one of the compartments isput out of operation by closing the booster steam valve, the level ofthe cooled water therein will automatically sink, for the chilledcontents of this particular chamber will I be forced outbecause thepressure in that chamber rises to condenser pressure. But enough of thewater will be trapped in the riser connected to that chamber to seal itand keep it from communicating with the other chambers. As this methodis fully set forth in my co-pending application, Serial No. 716,945, forpatent on Refrigerating apparatus, flied of even date herewith, thatpart of the apparatus herein described which gives this function istherefore not recited in 'the claims hereunto appended.

When, one of the boosters is turned on for purposes of saving steam asdescribed above, and condenser pressure is exerted in the correspondingevaporator chamber, the water to be chilled must be prevented fromentering this inactive chamber. This is necessary because the inactivechamber is now in free communication with the height.

the chamber which extends longitudinally between the partitions B andone end of the evap-' orator l; Each weir begins at the bottom andextends toward the top. Each of the weirs together with the adjacentportions of the wall of the evaporator I provides a space or well 88into which the water is admitted through the adjacent branch l3delivering to the well near the bottom, as shown in Figure 2, and acertain portion thereof will be vaporized at once as it flows over theweir. If desired each weir may have openings ll near the top throughwhich the water therein may be delivered. Such a construction has theadvantage that the proper distribution of water to the various chambersis more easily obtained and controlled, as it prevents slight variationsof vacuum from interfering with the flow of the refrigerant.

To carry away the water vapor, each of the chambers 4 5, 6, and I has anoutlet IS in the top leading to steam ejectors or steam jet boosters 20.These are in the form of L-shaped tubular members which communicate atone end with the outlets l8 and are connected to their opposite ends tothe conduit 9 into which they discharge.

Each ejector has a steam nozzle}! connected by pipe 22 to the steam lineH! and each branch pipe carries an admission and shut-off valve 23. Theejectors for the chambers 4, 5, 6, and I all discharge into the conduit9 leading to the condenser (not shown), but the ejector for the chamber4 is of much smaller size and capacity than the others and serves aspecial purpose described below. The chamber 4 is not provided with aweir but the inlet pipe I! extends from the bottom as high as the weirsIS in the other chambers. All of the weirs are, of course, of the sameIn operation, water to be cooled may enter all the chambers through thebranches I3 and the inlet pipe [2, and as part of it is vaporized, thewater vapor is removed by the steam ejectors through the pipe 9 andcompressed to the pressure in the condenser. The water, which is chilledby the vaporization of part thereof, passes out through the risers l4and the delivery conduit 3 as above set forth. So long as the steam jetsare supplied from the line ID the vacuum in the chambers remains low,but if any one of the steam jets is shut oil the absolute pressure inthe chamber to which that jet is connected, will increase and becomeequal to the pressure of the condenser. This pressure will depress thelevel of the inflowing water in the well l8 below the tops of the weiror openings IT in that chamber,

so that no more water can enter the chamber chambers.

risers, however, will be high enough so that some of the water will betrapped in the riser connected to the chamber which is not working, andwill seal the latter from below, and the greater pressure in thenon-operating chamber will be prevented from taking effect in any of theother operating chambers. This condition is shown in the chamber 1 onFigure 1.

In practice the evaporator will be operated by including all thechambers or by cutting out one or moreof the chambers 5, 6, and 1.Chamber 4 must always be in operation because it con-.

.rate of outflow. If this water level drops the valve is opened further,and if the water level tends to rise it is moved towards closedposition. The

steam jet for the chamber 4 is somewhat smaller than the other steamjets and is so proportioned that it will maintain the same vacuum'inthis chamber as in the other chambers which are working.

This is insured by admitting only a small amount of water through thesmall conduit i2, thereby establishing the temperature and pressure inchamber 4 as substantially the same as that in the other activechambers.I

It should be noted that the pipe i2 and the booster for the chamber 4are of such relatively small capacity that no substantial refrigeratingeffect is produced. The sole function of this booster and its chamber 4is to maintain the proper water level in the active chambers,irrespective of which ones are in use without necessitating themanipulation of any valves for putting any of the chambers into or outof service.

With all the chambers in communication with one another through therisers It, the cooled water therein tends to seek the same level in thechambers that are working, because each working chamber is subjected tothe pressure head of the cooled waterin the other working This levelwill be constant because the vacuum-maintained by the steam jets in allthe working chambers is the same. When any chamber is cut out ofoperation, the admission of further water thereto from the pipe 2 isprevented because the higher condenser pressure in that chamber forcesthe level of the infiowing water in the well a material distance downbelow the top, while the water already chilled in that particularchamber is forced out and that chamber is emptied except for a portionwhich remains in the riser pipe, at the level indicated in the riser Mof the chamber 1, for example, in Figure 1, to seal this chamber. Thepump 29' in the line of the conduit 3 insures the transmission of thecooled water to the place of use.

The end of the pipe 2 outside of the evaporator is shown as having aflange 30 to facilitate securing it to the outside of the chamber 4, soas to deliver through an inlet 3| to the portion of this supply pipewhich is inside of the evaporator i. The valve 26 is in the line of thispipe inside the evaporator, as are also the lever carrying the float,the connecting rod 28 and the arm 21. Hence, no stufiing box or packingneed be provided for this rod, such as would be necessary if the valve26 were outside of the evaporator. The casing for this valve has flangesto enable it to be joined on one side to a flange of a section of thepipe 2 inside the evaporator leading to the inlet 3|, where this sectionhas a similar terminal flange to enable it to be secured to the wall ofthe evaporator around the inlet 3|, the same as the outside pipe 2, andon the other side to another section leading to the first of the'remaining chambers. The inside partitions it have openings 32 so thatthe sections H can be secured by similar end flanges to the partitions 8around the openings 32, and the lateral branches l3 lead to openings 33in the weirs l6 adjacent the bottoms thereof. Pipe i2 is likewisesecured to the pipe' 2 by a flange at its lower end, and the branchesis. are similarly united to the weirs around the openings 33, thenumeral 38 indicating all of the flanges above mentioned.

It will be seen that, as illustrated in Figure 2, the level of theinfiowing water in any chamber which is operating is at a predetermineddischarge point in the well thereof, and is higher than the level of thechilled water in the bottom of any working chamber, where it collectsbefore passing out through the risers id. vaporization of part of thewater takes place as the incoming water flows downward from the upperportions of the wells iii and the pipe M, which is also, in effect, awell. As long as the water vapor is sumciently evacuated from anychamber by the members it, the level of the incoming water remains highenough to be discharged from the well, and when the vacuum is lessenedupon the stoppage of any one of the steam jet boosters, the increase ofabsolute pressure to condenser pressure within the chamber which is putout of operation empties that chamber because the pressure forces downthe level of the incoming waterso that no more vaporization isaccomplished and at the-same time it depresses the level of the chilledwater therein to the point indicated in connection with the riser Mconnected to the chamber i.

The system may be operated so that, when a chamber is cut off the totalquantity of refrigerant is correspondingly reduced. Then the samequantity of refrigerant as before flows through each of the remainingchambers and at the same rate. Or the operation may be such that thequantity of liquid remains as before, when one or more chambers arestopped and thus the body of refrigerant passes at an increased ratethrough the remaining chambers.

I claim:

1. A refrigerating construction comprising an evaporator containing aplurality of chambers, means for supplying a liquid refrigerant part ofwhich is to be vaporized in said chambers, means for evacuatingvaporized refrigerant from said chambers, means for delivering theremainder of the liquid refrigerant from said chambers, a valve in thesupply means on the inside of said evaporator, and a regulating elementin one of said chambers connected to said valve arranged to maintain theliquid in said chambers at a substantially constant level.

2. The method of producing and controlling rcfrigeration whichconsistsin dividing a liquid refrigerant into separate quantities,supplying each quantity independently from a common source, causing thedischarge of each quantity from a predetermined level to a lower leveland simultaneously vaporizing a portion thereof, and stopping thedischarge and vaporization of any one of said quantities by increasingthe pressure upon it and thereby depressing its surface below thedischarge level, without interrupting vaporization of portions of theremainder of said refrigerant.

3. The method of producing and controlling refrigeration which consistsin treating a liquid refrigerant in separate quantities by suppLvingeach quantity independently, maintaining a vacuum above each quantity,keeping the surface of each quantity at a predetermined level, causingthe discharge of each quantity from saidlevel under the influence ofsaid vacuum and simultaneously vaporizing a portion of said quantity,and stopping the discharge and vaporization of any one of saidquantities by decreasing said vacuum and thereby depressing the surfaceof said quantity below the discharge level without stopping vaporizationof portions of the remainder of said refrigerant.

4. The method of producing and controlling.

spaces to vaporize a part of the refrigerant therein, removing andcompressing the vapor so 7 formed, and increasing the pressure in anyone of said spaces to empty same and suspend the passage of refrigerant,thereinto while continuing the passage of refrigerant into the otherspaces.

5. The method of producing and controlling refrigeration consisting inpassing a liquid refrigerant through separate spaces, treating therefrigerant by creating a vaucum in each space and vaporizing a part ofthe refrigerant therein, removing and compressing the vapor so formed,and subjecting any of said spaces to the increased pressure of theremoved vapor from other spaces to empty the space so subjected and stopthe passage of refrigerant thereinto to suspend vaporization in thespace while continuing the passage of refrigerant into and thevaporization thereof in the remainingspaces.

6. A refrigerating construction comprising'an evaporator containing aplurality of chambers, means for delivering liquid refrigerant to each@Jfisfi'fis chamber, means for withdrawing said refrigerant,

independent evacuating means to facilitate vaporization of part of therefrigerant in each chamber, and connections whereby the pressure ineach chamber can be increased to empty same and suspend the delivery ofrefrigerant thereto and the vaporization therein while the remainingchambers continue to be active.

7. Refrigerating apparatus comprising an evaporator having aplurality-of chambers connected in parallel, evacuating means for eachchamber to reduce the pressure therein and to remove vapor therefrom, awell in each chamber having its upper opening above the bottom of thechamber, means common to all the chambers to introduce -refrigerant tothe well near its bottom, means to withdraw chilled refrigerant from thechambers, and means associated with the evacuating means toincrease thepressure in a chamber and thereby prevent the admission of refrigerantthereto.

8. Refrigerating apparatus comprislngan evaporator' having a, pluralityof chambers, evacuating means for each chamber to reduce the pressuretherein and to remove vapor therefrom, means to withdraw chilledrefrigerant from the chamber, means to start and stop the action of theevacuator to decrease or increase the pressure in the chamber, and meansincluding aweli in the chamber to admit refrigerating medium to thechamber when the evacuator is operating and to prevent such admissionwhen the evacuator is inoperative, without affecting the operation ofany other chamber.

9. Refrigerating apparatus comprising an evaporator having a pluralityof chambers, evacuating without interference with the admission ofrefrigerant to any other chamber.

/ FREDERICK H. HIIBBEBD.

'con'lance with the pressure maintained therein,

